The Difference between the Various RX Safety Eyewear Lens Types

Eye safety is one of the top concerns for any safety manager. In some cases, this safety comes in the way of not just any regular safety eyewear option but in the form of prescription safety glasses.

As you can probably tell the two may perform the same function but they are not created equal. In the case of prescription safety glasses the materials selected for the lenses need to not only keep foreign objects away from the wearer’s eyes but also allow for him/her to see the work at hand in a clear and crisp way. Safety managers should be aware of these differences because the options available will be limited based on the choice selected. Here are some valuable details about the diverse alternatives in the prescription safety lenses field.

Materials

Polycarbonate

One of the most popular and widely sought after materials for prescription safety eyewear is polycarbonate. Not only is this material offered in almost every color option but it is also one of the most impact resistant and thinnest choices. However, its main downside is how easily it can become scratched from regular wear. This medium-index material should be considered to be a middle ground between standard and high index plastics.

Standard Plastic

Generally found to be the cheapest safety lens material, standard plastic is the easiest to turn into a prescription lens. It is low-index and very scratch resistant, which makes this an excellent choice if the biggest needs are bulk quantities and accessibility.

High-Index Plastic

Not only is high-index plastic more scratch resistant than standard, it also boasts a much thinner size which helps to make lighter glasses. Still, there are some negative aspects; they are significantly more expensive than standard, they are not available in as many color combinations and it is tough to find them as bifocal or polarized.

Trivex

Introduced in 2001 as a competitor to polycarbonate, Trivex has some similar characteristics and some variances. The main resemblances are: light-weight, high impact resistance and 100% UV protection. Meanwhile, they have different optical clarities due to Trivex being created in a mold, which allows for a crisper image. Due to being a relatively new player there are not as many color options in this lens style.

Testing

All safety glasses fall under one of two performance classifications: basic impact or high impact.

Basic impact is tested via the “drop ball” test. The test is administered by dropping a one-inch diameter steel ball from 50 inches away directly onto the lens. As long as the lens is not chipped, cracked, broken or dislodged from the lens holder/frame it passes.

High impact is tested with a high velocity test. This one is performed by shooting a quarter-inch diameter steel ball directly at the lens at 150 feet per second. It also passes provided that there is no chipping, cracking, breaks or separation from the lens holder/frame. Lenses that have passed will have a “+” mark to indicate high impact approval rating.

In spite of all the similarities between the various types of lens materials the most important aspect when it comes to any safety equipment is making sure you get the right tool for the right job. Reviewing these valuable details on lenses can help you make that final decision. If you need more advice or are unsure what steps to take to bring the best prescription safety eyewear for your facility, don’t hesitate to contact your localORR Safety account manager. Our safety experts are always available and can help customize your eyewear safety solutions.